What is useful to know about breast anatomy when I'm breastfeeding my baby?

The most important message to embrace about breast anatomy is that there is an incredibly broad definition of what is normal. Human breasts are highly diverse and women of all shapes and sizes can have a long and meaningful breastfeeding journey. Typically, no matter your breast shape or size, about two thirds of your glandular tissue (that’s the part of the breast that produces the milk) sits within a 3cm radius from the base of your nipple. What this means is that it’s really important for your baby to draw as much of that tissue up into their mouth as possible, to get the best chance of easy and efficient milk transfer and avoid dragging and occluding ducts (also, ouch!). In some women, glandular tissue can extend into the axilla (armpit). This can cause some tightness and discomfort, especially when the milk first comes in, but usually settles down once feeding is established. The let-down (also known as the milk ejection reflex) varies greatly between women as well. You may or may not feel your let-downs, and that’s OK. Think of the let-down as a hormonal code which prompts your breasts to release milk to your baby. During the let-down, the milk ducts within the glandular tissue dilate, to let more milk flow seamlessly through. Breast tissue drag, caused by suboptimal fit and hold of baby at the breast, can interfere with the widening of the ducts and therefore impact on how easily your milk flows to baby. Your anatomy isn’t to blame for tissue drag, it all comes down to fine-tuning your unique feeding embrace with your baby, like pieces of a puzzle. Importantly, any new lump in the breast or armpit should be reviewed by a doctor, even if you’re breastfeeding.

Does the size of my breast affect my milk production or milk storage?

Are you worried your cup size might compromise your supply? Truth be told, it won’t. You’d be forgiven for thinking so, but the way your breasts look on the outside has no bearing on how much milk you can produce. Breast size is mainly determined by adipose (fatty) tissue, which doesn’t produce milk. Milk production occurs in glandular tissue within the breast and is driven by demand, rather than size. The higher the demand and the more effective the transfer of milk from breast to baby, the more milk gets produced. Breasts are specially designed to produce milk, regardless of how much fatty tissue they hold. The good news is, no matter what the size of your breasts, they’re biologically primed to respond to your baby’s needs. Never mind if one breast is slightly more generous in size than the other; that’s quite normal, and also won’t affect your milk supply. Bra shopping? Cup size matters. Breastfeeding? Don’t judge a breast by its cover!

Dr Melanie Mapleson
General Practitioner
44 Wills Rd, Woolooware NSW
(02) 9527 1188